There were no injuries and nobody was treated for any problems at the scene.

Under construction, the 10,000-seat, approximately $220 million PPL
Center is expected to be complete in time for the September season
opener of the Phantoms, the minor league affiliate of the Philadelphia Flyers.

Construction workers shut down the gas lines running into the arena after detecting the odor, then the workers were sent outside at 8:52 a.m., Henrick said.

UGI responded but the leak was already isolated by the time they arrived, according to UGI spokesman Joe Swope. The workers were allowed back into the building at 9:42 a.m., Henrick said.

There are four temporary gas lines running into the arena. UGI checked the lines as a precaution but found no problems.

"This was a damaged fuel line on a customer-end within the arena somewhere; it did not involve UGI facilities," Swope said.

"In a building like that, especially with people in the building, you're going to detect the odor of the natural gas long before it becomes potentially harmful," he said. "It sounds like the leak was detected very quickly."

The city and project officials will hold a news conference this afternoon at the arena related to the concrete pour of the ice floor.